This is a proposal to continue the work on steroid dynamics which we have carried on for several years and to extend our studies into new areas. We propose to determine whether splanchnic tissue is an important site of aromatization of androgens in men and to identify other tissue sites involved in aromatization and in 5 alpha-reduction of androstenedione and testosterone using men and animal models. We plan to determine whether liver disease, other than alcoholic cirrhosis, is associated with abnormalities in steroid dynamics. Since many of these abnormalities may be due to alterations in steroid-plasma protein binding, we plan to assess the role of protein binding as a modulator or estrogen and androgen entry into tissues and to examine the control of sex-steroid binding globulin in animal models.